Everyday
Does the Eiffel Tower change height?
The short answer
Yes. The tower is made of iron, and iron expands when it warms. Across the seasons the Eiffel Tower's height varies by up to about 15 centimetres, and in strong wind the top can sway around 6 to 7 centimetres.
Thermal expansion is unremarkable physics until you apply it to 7,300 tonnes of iron standing 330 metres tall. Warm the metal through a Paris summer and the whole structure lengthens slightly. Cool it through winter and it contracts again.
The official figures from the tower put the seasonal variation at up to around 15 centimetres. The sun-facing side warms more than the shaded side, so the top also leans gently away from the sun over the course of a day.
Wind moves it too, though less than people assume — the top sways in the range of 6 to 7 centimetres. Gustave Eiffel designed the open lattice specifically so the wind would pass through rather than push. The building breathes with the weather, and it was meant to.
Source
- The Eiffel Tower: key figuresSociété d'Exploitation de la Tour Eiffel